Method of making a printing wheel for printing a code on insulated wire



April 1969 J. R. JOHNSON 3,440,705

METHOD OF MAX A PRINTING WHE FOR PRINT A E ON INSULATED E iled Aug. 31, 1966 GRAVKNG PARATUS INVENTOR J OH N SON FIGQ4. BY

ATTORNEYS United States Patent US. Cl. 29-159 2 Claims ABSTRACT OF THE DISCLOSURE A wheel for printing a code on an insulated wire is provided by cutting a ring of metal from a tube. The code is then imprinted on the exterior surface of the ring. Thereafter, an annular groove is formed in this exterior surface of the ring by positioning the ring within a cylindrical die having an internal annular rib surrounding the ring to form the groove. A mass of resilient material is positioned within the ring and a compressive force exerted on the material to force the mass radially against the inner surface of the ring and thereby form the ring into the desired configuration conforming to that of the annular rib. The resulting printing Wheel is thus conformed to the exterior surface of an insulated wire upon which the code is to be printed.

This invention relates to a novel method of making a printing wheel for printing a desired code on insulated wire to facilitate identification of the wire.

As discussed in US. Patent No. 3,254,600, it is common practice to provide a printed code on the insulated portion of a wire for identification purposes. Normally, the printing is achieved by means of a printing wheel in the form of a solid disc member having an annular groove in its peripheral edge of proper cross-sectional shape to cradle the wire insulation. These wheels are relatively expensive and constitute a major cost factor in printing the code on an insulated wire.

While the above-mentioned patent provided certain economies in producing printing wheels, it has been dis covered that even greater economies may be effected by the method of the present invention.

In the prior art, it has been common to form an annular flange comprising the periphery of the wheel by means of drawing or spinning operations. An annular groove is then formed on the periphery by a roller spinning operation. These steps contribute substantial expense to the finished product due to the complexity of the required apparatus in conjunction with the high cost of labor due to the time involved.

With the foregoing in mind, it is accordingly a primary object of this invention to provide a greatly simplified method of forming a printing wheel which is considerably less expensive than methods heretofore employed, to the end that printing wheels may be supplied in large numbers for considerably less cost than has been possible heretofore.

More particularly, it is an object to provide an improved method of forming a printing wheel which completely eliminates the heretofore utilized drawing and spinning operations.

Briefly, the steps of the method of the invention involve cutting a ring of metal from the end of a tube. An appropriate code is then engraved on the periphery of the ring. An annular groove is then formed on the periphery of the ring of a cross-section which conforms to the diameter of an insulated wire upon which the code is to be printed. This groove is formed by a single step die press operation as opposed to spinning methods heretofore employed. Lastly, a washer element or disc may be ice inserted on each side of the ring to form the completed printing wheel for mounting on a printing apparatus.

In the foregoing method, considerably less expensive as well as time saving, steps are employed to the end that substantial economy is effected in the making of printing wheels.

A better understanding of the invention will be had by now referring to the accompanying drawing, in which:

FIGURE 1 is a perspective view illustrating an annular ring cut from a tube in accordance with a first step of the method and further illustrating the ring after a second step of the method has been carried out;

FIGURE 2 is a sectional view illustrating the ring being received in a die and press assembly preparatory to a further step of the method;

FIGURE 3 is a sectional view similar to FIGURE 2 illustrating a further step of the method; and

FIGURE 4 is an exploded perspective view illustrating the manner in which a printing operation is carried out on an insulated wire employing the printing wheel formed in accordance with the method of the present invention.

Referring first to FIGURE 1, there is shown an annular ring of metal 10 which is cut from a piece of tubular stock 11. An engraving apparatus as indicated at 12 is then employed to engrave a code C on the exterior surface or periphery of the ring 10.

Since the usual type of insulated wire to be printed is of a circular cross-section, it is necessary that the ring be formed of a cross-section to accommodate the wire during a printing operation. Accordingly, and in accordance with a further step of the invention, the ring 10 is positioned within a die assembly 13 which is mounted between a pair of coaxial plungers 14 and 15 of a press. The plungers 14 and 15 are arranged for movement toward and away from each other within the die assembly 13 by hydraulic means or the like (not shown).

The die assembly 13 includes a bottom ring 16, an insert ring 17, and a top ring 18 which are each diametrically split. The rings 16, 17, and 18 may be coupled in a co-axial relation by bolts or the like (not shown) and are receivable within a continuous retainer ring 19 as shown. The insert ring 17 includes an internal annular rib 20 of semi-circular cross-section for purposes to be described.

As shown, the ring 10 is positioned between the rings 16 and 18 so as to be surrounded by the annular rib 20 of the insert ring 17.

In accordance with a further step of the method, a substantially cylindrical mass or body of resilient material 21, such as synthetic plastic for example, is positioned between the plungers 14 and 15 within the ring 10. The material 21 is of greater axial thickness than the ring 10 and projects equidistantly above and below the ring for purposes to become apparent. In practice, the body of material 21 may include tapered peripheral portions 22 and 23 on opposite sides, respectively, of the ring 10.

A further step of the method is illustrated in FIGURE 3, wherein the plungers 14 and 15 move toward each other within the die assembly 13 to exert a uniform compressive force on the resilient material 21 which is confined within the ring 10 between the plungers 14 and 15. As the plungers 14 and 15 move toward each other, the material 21 is forced radially outwardly to bend the ring 10 into a configuration conforming to that of the annular rib 20. Accordingly, an annular groove 24 of semi-circular cross-section is formed on the periphery of the ring 10.

In actual practice the foregoing step is accomplished in a very few seconds since the resilient material reacts very quickly to the applied compressive force to bend or form the ring 10 into the illustrated configuration.

Upon movement of the plungers 14 and 15 away from each other, the die assembly 13 is disassembled and the split ring 17 is separated to free the ring 10 and the resilient material 21. The material 21 is sufficiently resilient to spring back to its original configuration thus enabling the material 21 to be easily removed from the ring 10. In practice, the body of resilient material 21 is capable of repeated use in the method of the invention.

By making the die assembly, of the illustrated construction, the center ring 17 may be removed and a ring having an annular rib of different size from that of rib substituted so that annular grooves of different dimensions may be formed with the same remaining components of the press.

Referring now to FIGURE 4, the manner in which the printing wheel is used will be clear. In accordance with a final step of the method, a pair of circular discs or washers 25 and 26, having tapered peripheral edges, are inserted against opposite sides of the ring 10. The combined thicknesses of the discs 25 and 26 may be substantially the same as the axial extent or width of the ring 10 to thereby provide the appearance of a solid disc or wheel.

The washers 25 and 26, and the interposed ring 10, are then received on an arbor 27. A Washer 28 and nut 29 are then received on the arbor with the nut 29 threaded on a threaded portion 30 of the arbor. The disc 25 seats against a shoulder 31 provided on the arbor.

When carrying out a printing operation, the lower end of the printing wheel is passed through an ink trough 32 as it rotates to pick up the ink and effect a printing on a wire 33. A pressure roller 34 is employed to provide pressure on the wire 33. The wire 33 is simply drawn forwardly in the direction of the arrow thereby rotating the wheel and pressure roller.

The provision of the discs 25 and 26 within the ring 10 will prevent ink in the trough 32 from being picked up by the interior wall surface of the ring 10 as the same rotates. The exterior taper about the peripheries of the discs 25 and 26 is necessary to accommodate the annular groove 24 when the discs are inserted within the ring 10.

The foregoing method provides a very economical printing wheel as compared to conventional types which often require expensive drawing and spinning operations in their manufacture. Moreover, by the method of this invention, printing wheels may be produced in significantly less time than has been required heretofore.

While the material 21 is referred to as a resilient material, this terminology is meant to include any type of malleable or semi-resilient material having flow characteristics for translating forces applied normally thereto into radial directions.

What is claimed is:

1. A method of providing a printing wheel for printing a code in insulated wire, comprising the steps of: cutting a ring of metal from a tube; providing a code on the exterior surface of said ring; positioning said ring within a cylindrical die having an internal annular rib surrounding said ring; positioning a mass of resilient material within said ring; and exerting a compressive force on said mass to force said mass radially against the inner surface of said ring and thereby force said ring into a configuration conforming to that of said rib to thereby form an annular groove in said exterior surface of said ring after providing said code thereon, the cross section of said groove being rounded to conform to the exterior surface of said insulated wire.

2. The method of claim 1, including the subsequent step of inserting washer elements having tapered edges against opposite sides of said ring.

References Cited UNITED STATES PATENTS 1,715,138 5/1929 Lothrop 83-179 2,748,463 6/1956 Mueller 72-62 X 3,162,940 12/1964 Kuhn 29-421 3,254,600 6/1966 Storm et al. 101-4012 THOMAS H. EAGER, Primary Examiner.

US. Cl. X.R. 

